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ignoramous·

Previous discussions:

2016: https://news.ycombinator.com/item?id=12166585

2018: https://news.ycombinator.com/item?id=17280239

Community responses:

- https://news.ycombinator.com/item?id=12216680

- https://news.ycombinator.com/item?id=12179222

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Thanks! Here's an annotated list of all those (plus chris_wot's and a couple others):

Why Uber Engineering Switched from Postgres to MySQL (2016) - https://news.ycombinator.com/item?id=17280239 - June 2018 (47 comments)

Re: Why Uber Engineering Switched from Postgres to MySQL - https://news.ycombinator.com/item?id=12179222 - July 2016 (67 comments)

Why Uber Engineering Switched from Postgres to MySQL - https://news.ycombinator.com/item?id=12166585 - July 2016 (294 comments)

Thoughts on Uber’s List of Postgres Limitations - https://news.ycombinator.com/item?id=12216680 - Aug 2016 (103 comments)

A PostgreSQL response to Uber [pdf] - https://news.ycombinator.com/item?id=14222721 - April 2017 (82 comments)

Why we lost Uber as a user - https://news.ycombinator.com/item?id=12201353 - Aug 2016 (285 comments)

Uber's Move Away from PostgreSQL - https://news.ycombinator.com/item?id=12223216 - Aug 2016 (15 comments)

The response was:

https://news.ycombinator.com/item?id=14222721

Even though 99.9% of applications will never run into Uber's issues, it's been 4 years and 4 major versions later, and I'd love to review these complaints and see if they still apply to PG 13.

Wait until 14 for that comparison and it'll look much better. Bottom up index deletion helped solve some of the write amplification issues.

There is also index deduplication in Postgres 13 and the B-Tree enhancements in Postgres 12. All of these enhancements significantly improved the situation for workloads affected by what the blog post calls write amplification. (I myself call this phenomenon index version churn, since it is more descriptive and has less baggage.)

I was the author of all of the above, including the Postgres 14 work you mentioned (though Anastasia Lubennikova was the primary author of index deduplication). To me it feels like one very large project -- the effects are cumulative, and each major Postgres version had B-Tree work that built on the last release in one way or another.

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